Volume change compensated silicon-silicon oxide-lithium composite material having NANO silicon particles embedded in a silicon:silicon lithium silicate composite matrix, and cyclical ex-situ manufacturing processes

Abstract

A method for producing a volume change compensated silicon: silicon oxide: lithium composite (SSLC) material is disclosed. The method includes producing an initially prelithiated SSLC material; delithiating the initially prelithiated material to produce a delithiated SSLC material; and performing at least one iteration of a volume change compensation process involving: (a) re-prelithiating the delithiated SSLC material to produce a re-prelithiated SSLC material; and (b) delithiating the re-prelithiated SSLC material produced in (a), wherein at least one of the following is satisfied: (i) prior to performing the at least one iteration of the volume change compensation process the initially prelithiated SSLC material is essentially completely lithiated; and (ii) at least one iteration of the volume change compensation process produces a re-prelithiated SSLC material that is essentially completely prelithiated. In a final iteration of the volume change compensation process, delithiating the re-prelithiated SSLC material produced in (a) completely delithiates the re-prelithiated SSLC material to produce the volume change compensated SSLC material. The aforesaid process is performed prior to, or ex situ with respect to, the fabrication of an anode that contains the produced volume change compensated SSLC material.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the priority of U.S. Provisional Application No. 62 / 383,372, entitled “Silicon-Silicon Oxide-Lithium Composite Material Having Nano Silicon Particles Embedded In A Silicon-Silicon Lithium Silicate Composite Matrix, And Related Manufacturing Processes” filed on Sep. 2, 2016 and U.S. Provisional Application No. 62 / 478,535, entitled “Silicon-Silicon Oxide-Lithium Composite Material Having Nano Silicon Particles Embedded In A Silicon: Silicon Silicate Composite Matrix, And Related Manufacturing Processes” filed on Mar. 29, 2017.TECHNICAL FIELD[0002]Aspects of the present disclosure relate to a silicon-silicon oxide-lithium composite (SSLC) based material having nano silicon particles embedded in a silicon:lithium silicate composite (Si:LSC) matrix, a process for preparing the same, and manufacturing processes relating thereto, including cyclical ex situ manufacturing processes. The SSLC based material is useful as a ne...

AI Technical Summary

Benefits of technology

The present disclosure provides a simple and cost-effective process for producing a commercially scalable, reliable, and useful SSLC material that can be used as a negative electrode material in lithium-ion batteries. The process allows for the complete delithiation of the material before use in battery manufacturing, making it compatible with typical battery processes. The resulting material exhibits uniformity, low volume change and irreversible capacity loss compared to prior SiOx-based anodes. This material can be easily formed into a good laminated electrode structure without forming a deleterious gel, even when a relatively large amount of lithium has been used to prelithiate SiOx particles.

Problems solved by technology

As indicated above, high capacity silicon oxide based anodes offer excellent cyclic performance at higher loading density compared to pure silicon based anodes, but silicon oxide based anodes suffer from low initial efficiency.

Although irreversible capacity loss can be reduced in the manner disclosed by U.S. Pat. No. 7,776,473, the inventors of the present application have found that prelithiation of SiOx in accordance with the teachings of U.S. Pat. No. 7,776,473 (i.e., introducing lithium into the SiOx prior to its use in the fabrication of an anode or as an anode material), which is performed by ball milling solid state materials (i.e., solid silicon oxide powder and metallic lithium powder), results in incomplete and non-uniform lithiation.

That is, complete, uniform prelithiation of SiOx by ball milling solid state materials in the manner disclosed by U.S. Pat. No. 7,776,473 is difficult to achieve.

U.S. Pat. No. 7,776,473 discloses that the rate of diffusion of metallic lithium into solid SiOx is low, making it difficult for metallic lithium to uniformly penetrate into the SiOx.

Furthermore, the use of larger amounts of metallic lithium powder during ball milling to potentially provide a greater concentration of lithium available for diffusion into SiOx is not feasible in view of safety concerns due to the highly reactive nature of lithium, as well as the need to remove decomposed products during the ball milling process.

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